The implementation of asymptomatic SARS-CoV-2 testing among hospitalized patients and healthcare workers (HCWs) is one of the containment measures introduced during the COVID-19 pandemic. These protocols, although costly, plays a substantial role in minimizing the risk of nosocomial infections — diseases contracted in a hospital setting. However, in August 2022, the guidance suggesting asymptomatic testing was withdrawn, but presenting an objective assessment based on data becomes difficult due to the simultaneous changes in infection prevention strategies, fluctuation in community transmission rates, and the reduction in detection rate corresponding to decreased testing.
Computational modeling, therefore, provides a reliable means to estimate the impact of these changes. A simulation exploring SARS-CoV-2 transmission within an English hospital was conducted to assess various asymptomatic testing methodologies. These include symptomatic testing of patients and HCWs, testing of all patients on admission with an optional repeat testing schedule on days 3 and 5–7, and twice-weekly asymptomatic HCW testing with a 70% participatory rate.
Analyses revealed that asymptomatic patient testing at admission could reduce nosocomial SARS-CoV-2 infection rates by 8.1–21.5%. However, additional testing on days 3 and 5–7 post-admission did not significantly decrease infection rates further. Regular asymptomatic HCW testing can trim the fraction of infected HCWs by 1.0-4.4% and reduce monthly absences by 0.4–0.8%. However, these testing protocols require millions of tests, pushing the total to nearly 30 million.
The most efficient strategy, in terms of testing required to avoid a single patient infection, was to test asymptomatic patients upon admission. Conversely, the least efficient method involved repeated testing of patients in combination with twice-weekly asymptomatic HCW testing in a low prevalence environment.
Therefore, admitting test for patients can reduce the rate of nosocomial SARS-CoV-2 infections, but post-admission testing offers only marginal benefits. Regular asymptomatic HCW testing is optimally beneficial in higher prevalence or low community transmission scenarios. However, comprehensive health-economic evaluations should guide the establishment of the cost-effectiveness of these strategies.
Source: https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-023-08948-9